GENEVA -- In a 17-mile circular tunnel curving beneath the Swiss-French border, scientists are poised to re-create the universe's first trillionth of a second.
The aim of the audacious undertaking -- whose centerpiece is the Large Hadron Collider, the largest, most powerful particle accelerator ever constructed -- is to solve one of the most perturbing puzzles of physics: How did matter attain mass and form the cosmos? Even Einstein couldn't nail that one.
The collider and its multibillion-dollar array of ancillary instruments are designed to re-create and identify the most infinitesimal of subatomic substances -- the material that built the galaxies -- as they blaze into existence with fantastic energy and disappear with such rapidity as to make the blink of an eye seem an eternity.
The project involves half the planet's particle physicists, drawn from 80 countries.
Roughly 800 American researchers are participating with 7,000 other scientists in the $8 billion project overseen by the European Organization for Nuclear Research, better known by its French acronym, CERN.
Hopes are high that the CERN effort -- billed as the largest science experiment ever -- will yield astonishing glimpses into black holes, hidden dimensions and other mysteries of space-time.
Any big result will provide a much-needed jolt to the stuck-in-the-mud field of particle physics, which has seen little in the way of major advances in the past three decades.
"There is a definite giddy sense that we're nearing a watershed," said George Brandenburg, a Harvard University physicist involved with one of the major experiments soon to get under way at CERN. "At the very least, we should be seeing some very intriguing stuff when the protons start to collide. As to whether we can wrap up the universe with a nice pink bow -- well, who knows? But for sure this is a serious shot at it."
The Hadron Collider, named for the category of tiny matter that includes protons and neutrons, is scheduled to begin test runs later this year and should be revved to full strength in early 2008, according to CERN.
The collider, conceived in 1994, is designed to forge the blizzard of energies and particles unloosed in the first picosecond of the Big Bang, although on a much smaller scale. According to prevailing scientific theory, the cosmos was born in an instant roughly 13 billion years ago.
"It's basically a time machine," said Julia Hoffman, a particle physicist from Southern Methodist University in Texas. "We're going back to the birth of everything and doing it again."
Most of the action will occur in an enclosed underground track roughly the size of a subway tunnel, forming a 17-mile circle lying an average of 328 feet beneath a bucolic countryside of dairy farms and rustic villages set against the snow-capped Alps.
Using super-conducting magnets, the collider will accelerate two streams of protons -- positive-charged particles that are inside every atom -- to more than 99.9 percent of the speed of light, or about 186,000 miles per second. Then, earning its name, the contraption will shift the protons into a collision course, causing them to smash head-on.
The experimenters are especially intent on tracking down an elusive entity called the Higgs boson, also known as the "God particle," a speck from the field of the same name that physicists believe somehow adheres to everything else.
Many physicists believe the Higgs represents the key to the "standard model" of physics, the elegant theory devised in the early 1970s that goes a long way toward explaining the most basic bits of the universe and how they interact.
"Either we find the Higgs and say, 'Yes!' because much of what we thought we knew about how the universe works is right," said Steven Nahn, a particle physicist from the Massachusetts Institute of Technology and one of the researchers. "Or we scrap the standard model and go back to the drawing board."
Scientists believe the high-speed crash of protons -- occurring at a rate of 600 million per second when the accelerator is running full-tilt -- will shed bits of elusive debris, such as the Higgs boson. Such bits flared into being at the dawn of time, but have been more or less invisible since. Scientists believe they can only be re-created under conditions similar to the Big Bang.
There may be no "Eureka" moment at CERN. Instead, some 3,000 computers will sift through boggling amounts of data, equivalent to 1 percent of all data on Earth (that is, all content from newspapers, magazines, scientific studies, stock market indices, government recordkeeping and so on).
The scientists and their machines will be looking for peculiar bursts of energy or inexplicable pings of matter. According to physicists, the Higgs boson, if it exists, will follow a unique trajectory that will permit researchers to make a positive identification.
The subterranean course is broken by four vast chambers housing intricate machines with which scientists hope to monitor what they prosaically describe as "events," tinier-than-atom particles splintering into even tinier shards; the near-instantaneous creation and decay of "miniature" black holes; and perhaps even rips in the space-time fabric that will allow a peek into dimensions beyond.
"Every collision will produce an event," said Joao Guimaraes, an experimental physicist from Harvard. "The huge challenge is to figure out which events are truly different or significant, which events may portend truly new insight into the universe."
Little of the research at CERN may be "useful" in the sense of immediately leading to nifty new consumer gizmos or finding hard cures for specific woes, whether climate change or cancer.
"These experiments are driven pretty much by pure curiosity, the human need to know," said Frank E. Taylor, a high energy physicist at MIT. "Particle physics doesn't necessarily translate into making better mousetraps."
Particle physics, also known as high energy physics, ranks among the most rarefied realms of science. It studies the elementary constituents of matter and energy, the most basic building blocks of nature. The experiments require big brains, big money and big equipment.
And if the research falls flat?
"That would be just as exciting to experimenters; it would mean we'd be looking into the face of something totally unexpected and new, instead of just confirming our expectations," said Christoph Paus, an experimental particle physicist from MIT.
He paused, then acknowledged with a sigh: "But it would also be a PR disaster. The sort of thing that people who don't understand science use to ridicule science."